This application is based on Japanese Patent Application No. HEI-9-163148 filed on Jun. 19, 1997, the entire contents of which are incorporated herein by reference.
a) Field of the Invention
The present invention relates to a micro structure and its manufacturing method, and more particularly to micro machines and a manufacturing method suitable for fabrication of micro machines.
b) Description of the Related Art
As a manufacturing method for micro structures, techniques of Lithographie Galvanoformung Abformung (LIGA) are known. Conventional LIGA techniques will be briefly described.
A photoresist film is formed on a conductive support substrate. This photoresist film is locally exposed with X-rays by using a LIGA mask having a high contrast, and thereafter developed and patterned. Regions where the photoresist film is removed are filled with metal by galvanizing. As the photoresist film is removed, a micro structure made of metal can be formed.
With LIGA techniques, it takes generally several hours to expose and develop a photoresist film. A photoresist mask having a high contrast is also required.
It is an object of the present invention to provide a method of manufacturing a micro structure having a shortened process time.
It is another object of the present invention to provide a composite micro structure made of a combination of different materials.
According to one aspect of the present invention, there is provided a method of manufacturing a micro structure comprising the steps of: preparing a laminated substrate of two layers including a first film and a second film in tight contact with the first film, the second film being made of a material capable of being etched with synchrotron radiation light; disposing a mask member with a pattern in tight contact with a surface of the second film of the laminated structure or at a distance from the surface of the second film, the pattern of the mask member being made of a material not substantially transmitting the synchrotron radiation light; and applying the synchrotron radiation light on a partial surface area of the second film via the mask member to etch the second film where the synchrotron radiation light is applied and to expose a partial surface area of the first film on a bottom of an etched area.
Since the second film is etched by applying radiation light, a process time can be shortened as compared to LIGA techniques which utilizes exposure and development processes.
According to another aspect of the present invention, there is provided a micro structure comprising: a first film made of a material having an etching resistance to radiation light different from an etching resistance of polytetrafluoroethylene; and a second film in tight contact with the first film and made of polytetrafluoroethylene, the second film being patterned, and a surface of the first film being exposed in an area where a pattern of the second film is not formed.
By using this micro structure, a micro machine made of plastics can be formed.
According to another aspect of the present invention, there is provided a micro structure comprising: a polytetrafluoroethylene film having a through hole; and a metal member filling the through hole.
A micro structure can be formed by selecting each material of each region of the structure so as to satisfy the mechanical and electrical characteristics required for the region.
As described above, it is possible to perform micro processing by using radiation light. A micro composite material can be formed by filing a micro space in a micro structure with another material.